Article of footwear

ABSTRACT

An article of footwear comprises an upper portion which is dimensioned to at least partially enclose a user&#39;s foot, a sole portion connected to the upper portion and a solid microwaveable, insole shaped heating pad. The sole portion includes a pocket which is dimensioned for receipt of the heating pad. The article is adapted for removal and insertion of the heating pad by means an openable fastener which connects the upper portion from the sole portion. The invention also relates to a method of heating a foot comprising the step of providing an article of footwear according to the invention, removing the heating pad from the pocket of the article of footwear, heating the heating pad in a microwave for a suitable amount of time, inserting the heating pad into the pocket of the article of footwear and placing the article of footwear onto a users foot.

The invention relates to an article of footwear, and specifically aslipper. In particular, the invention relates to an article of footwearwhich is adapted to provide heat to a users foot. The invention alsorelates to a method of heating a users foot using the article offootwear of the invention.

There are a number of known shoes, boots or slippers of the type havingmaterial inserts or packs in the lining or sole, which are suitable forheating. These generally fall into one of three types. The first typeconsists of a natural material such as corn, wheat or nuts which ishoused in an encapsulant which itself can be heated, along with the shoein which it is carried, in a microwave. One problem with this type ofmaterial is that it's heat retention characteristics are poor, as itstays warm for only about 15 minutes. Additionally, as the naturalmaterial only holds a very small amount of water, the equilibriumtemperature of the material does not get above 80° C. Further, uponheating, the water can escape from the natural material as water vapourresulting in a decrease in the amount of water over time and aconsequential decrease in the equilibrium temperature of the material.Further, the nature of the material is such as to give off an odourduring heating which for most people is unacceptable. A further, major,drawback of these types of products is that bunching can occur, thisbeing the natural tendency of the material when agitated to migrate intolow pressure areas of the article of footwear. Generally these areas areones which do not require heat.

A further type of microwaveable insert comprises the use of a dessicantinstead of a natural material. While the use of a dessicant overcomesthe odour problem, it has been found to be ineffective in overcoming theheat retention or bunching problem. The heat retention problem is due,in part, to the small amounts of water that dessicant can hold.

A further type of microwaveable insert for shoes and slippers comprisesan encapsulated ge. Generally these gels include a thickening agent,normally a super absorbent polymer. Due to the presence of a thickeningagent, the gels have a very poor thermal conductivity, due to the factthat the liquid cannot generate convective currents. Thus, when heatedin a microwave, hot spots can occur within the insert.

Due to the poor thermal conductivity within such products, it isgenerally necessary when microwaving the insert to microwave it for aperiod of time on one side, and then turn the product over and microwaveit for a further period of time, with a view to homogenising the amountof heat dissipated from the surfaces of the insert. Often, tosufficiently microwave one of these products, three or more microwavingsteps are required.

International Patent Application Number WO94/28834 in the name of JMKInternational Inc. describes (in FIGS. 3 and 4) a microwaveable slipper.The slipper comprises a number of microwaveable heating pads which areintegrally built into the sole and upper portion of the shoe. As such,in order to heat the product it is necessary to insert the whole productinto a microwave.

STATEMENTS OF INVENTION

Surprisingly, the Applicant has realised a number of problems inherentin using the slipper disclosed in International Patent ApplicationWO94/28843. A first problem is the problem of malodour being produced asa result of microwaving the whole slipper. As will be readily evident tothe reader, as a user generally uses a slipper without socks, theslippers are prone to becoming soiled with sweat, dirt from the usersfeet, dead skin etc. Thus, when the slipper is heated, it is prone toproducing a bad smell. This problem is further exacerbated by the factthat most microwaves are predominantly used to heat or reheat foodproducts. As such, one would be quite disinclined to place a foodproduct in a microwave which had just been used to heat a slipper.Likewise, if the sole of the slipper has picked up any dirt, it islikely that the user will be less inclined to place it in a microwave.

Accordingly, the invention provides an article of footwear comprising anupper portion and a sole portion, the sole portion being connectable tothe upper portion and including a pocket for receipt of a microwaveableheating pad, wherein the article is adapted for removal and insertion ofthe heating pad.

Thus, an article of footwear according to the invention obviates theproblems described above due to the fact that the microwaveable heatingpad may be easily removed from the article of footwear and placed intothe microwave for, heating in the absense of the article of footwear.

In a preferable embodiment of the invention, the upper portion and thesole portion are detachable along at least a portion of a circumferenceof the article to allow access to the pocket for insertion and removalof the microwaveable heating pad.

In one embodiment of the invention, the upper portion and the soleportion are connected by means of a detachable fastener, such as, forexample, a zip. Many other types of detachable fasteners are envisagedsuch as, for example, velcro, a hook and eye arrangement, buttons, pressstuds, and the like. In one embodiment of the invention, the openablefastener extends completely around the circumference of the article offootwear. Alternatively, the openable fastener may only extend along aportion of the article of footwear, such as, for example around a heelof the article of footwear.

In one embodiment of the invention the pocket is dimensioned for receiptof an insole-sized microwaveable heating pad.

Typically, the upper portion is adapted to at least partially enclose ausers foot, and includes a base upon which, in use, a users foot rests.Generally, the base is formed from a fabric material.

In one particularly preferred embodiment of the invention, the articleof footwear includes a solid, microwaveable, heating pad which isdimensioned to fit into the pocket of the article of footwear.

In one embodiment, the heating pad comprises a mixture or ferrite andsilicone. Typically, the heating pad comprises a mixture of ferrite andsilicone in a ratio of between 4:1 and 1:4 (W/W). In a preferredembodiment, the ratio of ferrite and silicone is approximately 2:1(W/W).

Preferably the sole portion of the article of footwear includes aninsulating layer located underneath the pocket. Typically the insulatinglayer comprises a foam cushion. Ideally, the foam cushion comprises EPDMfoam. Suitably, the sole portion includes an outsole. In one embodiment,the outsole comprises a thermoplastic elastomer.

The invention also relates to an article of footwear comprising:

-   -   an upper portion dimensioned to at least partially enclose a        users foot;    -   a sole portion connectable with the upper portion; and    -   a solid microwaveable insole-shaped heating pad, wherein the        sole portion includes a pocket which is dimensioned for receipt        of the heating pad and wherein the article is adapted for        removal and insertion of the heating pad.

The invention also relates to a method of heating a foot comprising thesteps of:

-   -   providing an article of footwear according to the invention;    -   removing the heating pad from the pocket of the article of        footwear;    -   heating the heating pad in a microwave for a suitable amount of        time;    -   inserting the thus-heated heating pad into the pocket of the        article of footwear; and    -   inserting the foot to be heated into the article of footwear.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription of an embodiment thereof, given by way of example only, withreference to the accompanying drawings in which:—

FIG. 1 a is a side elevational view of an article of footwear accordingto the invention;

FIG. 1 b is an elevational view from an opposite side of the articlefootwear of FIG. 1 a;

FIG. 2 a is a side elevational view of the article of footwear of FIG. 1a with the upper portion shown partially detached from the sole portionrevealing a pocket into which a microwaveable heating pad is receivable;

FIG. 2 b is a view similar to FIG. 2 a showing a microwaveable heatingpad partially inserted into the pocket of the sole portion;

FIG. 3 is an exploded view of an article of footwear according to theinvention;

FIG. 4 is a plan view from above a sole portion forming part of thearticle of footwear of FIG. 1 a; and

FIG. 5 is a sectional view of the sole portion of FIG. 4 taken along thelines V-V of FIG. 4.

Referring to the drawings, and initially to FIGS. 1, 2 and 3, there isillustrated an article of footwear, specifically a slipper, andindicated generally by the reference numeral 1. The slipper 1 comprisesan upper portion 2 which is shaped to partially enclose a users foot,and a sole portion 3 which includes a pocket 5 for receipt of amicrowaveable heating pad 6. The upper portion 2 and sole portion 3 areconnected by means of a detachable fastener in the form of a zip 7 whichextends completely around a circumference of the slipper 1.

In more detail, and referring to FIG. 3, the upper portion 2 is formedof a thick cotton plush material which at least partially encloses theusers foot and includes a fabric base portion 4 upon which, in use, theuser's foot abuts. A first part of the zip 7 extends round acircumference of the base 4 of the upper portion 2.

The sole portion 3 comprises an outsole 10 formed of a thermoplasticelastomer having a second part of the zip 7 attached along an uppercircumference thereof. The sole portion 3 additionally includes an EPDMcushion 11 which is located within the outsole 10 and which, in use,insulates the heated insole and deflects heat upwards towards a foot ofa user. The pocket 5 for receiving the microwaveable heating pad 6 islocated within the sole portion 3 directly above the EPDM foam cushion11. As is clearly illustrated in FIGS. 3,4 and 5, the microwaveableheating pad has an insole shape and is dimensioned for fitting snuglywithin the pocket of the sole portion 3.

The microwaveable heating pad 6 comprises a 2:1 (W/W) mixture of ferriteand silicone, which is formed into the shape of an insole.

In use and referring to FIGS. 2 a and 2 b, the microwaveable heating pad6 is first removed from a slipper 1 by opening the zip 7 to reveal theheating pad 6 within the sole portion 3. The pad 6 is removed from thesole portion 3 and placed in a microwave for heating for a suitableperiod of time. Thus, for example, the pad may be heated by a microwaveon full power for 30 seconds. Once heated the pad 6 is removed by themicrowave and placed within the pocket 5 of the sole portion 3 of theslipper 1. The pad 6 is then fixed in place within the slipper 1 byattaching the upper portion 2 and the sole portion 3 by means of the zip7. The slipper 1 may then be worn by a user to heat the users foot.

Although the present invention is described primarily with reference toa slipper, it will be appreciated that the invention can be applied toany article of footwear, such as, for example, a shoe, a boot, a runningshoe, a football boot etc. Likewise, although the heating pad isdescribed as comprising a mixture of ferrite and silicone, it will beappreciated that any other suitable solid microwaveable material may beused without departing from the invention. Moreover, it will beappreciated that the openable fastener connecting the upper portion andthe sole portion does not need to extend completely around thecircumference of the article of footwear. In this regard, an opening maybe provided on the article of footwear which extends around only aportion of the circumference of the article of footwear and throughwhich the microwaveable heating pad may be inserted into the pocket.Such an opening may be closed by means of a zip, or by any othersuitable closure such as, for example, a velcro fastener or the like.

The invention is not limited to the embodiments here and beforedescribed which may be varied in both construction and detail withoutdeparting from the

1. An article of footwear comprising of an upper portion and a soleportion, the sole portion being connectable to the upper portion andincluding a pocket for receipt of a microwaveable heating pad, whereinthe article is adapted for removal and insertion of the microwaveableheating pad.
 2. An article of footwear as claimed in claim 1 in whichthe upper portion and the sole portion are detachable along at least aportion of a circumference of the article to allow access to the pocketfor insertion and removable of the microwaveable heating pad.
 3. Anarticle of footwear as claimed in claim 2 in which the upper portion andthe sole portion are connected by means of a detachable fastener such asa zip.
 4. An article of footwear as claimed in claim 1 in which thepocket is dimensioned for receipt of an insole-sized microwaveableheating pad.
 5. An article of footwear as claimed in claim 1 in whichthe upper portion is adapted to at least partially enclose a user'sfoot, and includes a base upon which, in use, a user's foot rests.
 6. Anarticle of footwear as claimed in claim 1 including a solid,microwaveable, heating pad which is dimensioned to fit into the pocket.7. An article of footwear as claimed in claim 6 in which the heating padcomprises a mixture of ferrite and silicone, optionally in a ratio of2:1 (W/W)
 8. An article of footwear as claimed in claim 1 in which thesole portion includes an insulating layer located underneath the pocket.9. An article of footwear comprising: an upper portion dimensioned to atleast partially enclose a user's foot; a sole portion connectable withthe upper portion; and a solid, microwaveable insole-shaped heating pad,wherein the sole portion includes a pocket which is dimensioned forreceipt of the heating pad, and wherein the article is adapted forremoval and insertion of the heating pad.
 10. A method of heating a footcomprising the steps of: providing an article of footwear according toany of claims 6 to 8; removing a heating pad from the pocket of thearticle of footwear; heating the heating pad in a microwave for asuitable amount of time; inserting the thus-heated heating pad into thepocket of the article of footwear; and inserting the foot to be heatedinto the article of footwear.